This application relates generally to machine-readable symbols. More specifically, this application relates to methods and systems for fabricating, acquiring, and processing machine-readable symbols.
Since their origins in the late 1940's, barcodes and other types of machine-readable symbols have become ubiquitous. They are used in a wide range of applications to identify items in a way that may be understood by a variety of devices. Perhaps the most common example is the use of barcodes to identify retail products with the Global Trade Item Numbers (“GTIN”) or Universal Product Code (“UPC”) symbologies. These systems are examples where machine-readable symbols are used to identify generally fungible products for sale, with information encoded in the barcode to identify characteristics of products being sold, including such information as an item number, a weight of the product, a price for the product, and the like. Other barcode symbology uses that identify classes of products are implemented in any number of inventory-based systems, such as in factories that use barcodes to track component supplies and to automate reordering when supplies of certain components are near depletion.
Other types of systems assign unique barcodes to items rather than assigning barcodes to groups of items. One of the more important of these is the GS1 supply-chain system, which implements a series of standards that are designed to improve supply-chain management. In combination with other standards, barcode standards are promulgated in this system to allow unique identification of products in manufacturing and other contexts. The Air Transport Association (“AITA”) implements a system of barcodes on aircraft boarding passes, a system that is tied to security and safety applications, and the use of barcodes in managing access to entertainment events have also become increasingly widespread.
Barcodes are also used for unique identification of living beings, notably in biological research in which animals are tagged with barcodes to track individual the behavior of individual animals, particularly in large-population environments where individual identification of the animals is otherwise difficult (such as for the tracking of behavior of bees in hives). Barcodes have also been used for the identification of human beings, such as in medical environments where wristbands having symbols that encode patient information are deployed.
While many deployments of machine-readable symbols are effected by attaching labels to items with printed barcodes, there are other implementations in which the symbols are incorporated directly onto the part being marked. This may be accomplished by such techniques as laser etching, chemical etching, dot peening, casting, machining, and other operations, and is particularly common in supply-chain applications.
The very ubiquity of machine-readable symbols means that there are many different circumstances in which the symbols may be difficult to read reliably: this may be because, among other reasons, the symbol itself is of poor quality; because the shape, color, or configuration of an object on which it is instantiated presents imaging challenges; or the environment in which it is to be read presents challenges. While a number of processing techniques have been developed to address such difficulties, many of these remain ineffective under a variety of conditions so that a need remains in the art for improved acquisition techniques.
In addition, many applications for machine-readable symbols introduce the risk of a variety of types of fraud. Software is widely available, both on the Internet and through other commercial avenues, that allow individuals to generate barcode symbologies that may be improperly affixed to items. Fraud can also be committed by copying barcodes and inappropriately attaching them to items so that the items are deliberately misidentified. Such copying is, moreover, not limited to the copying of barcodes to be attached to items but can also be committed with direct-part marks that are incorporated directly on items by examining and reproducing the marks improperly. Such fraud can not only have significant financial consequences, but can also have the effect of interfering with supply-chain monitoring and scenarios can even be envisaged in which such copying is used to commit batteries and other physical crimes against individuals through the deliberate mislabeling of medications, medical parts, and even the patient himself. There is accordingly also a need in the art to enhance the security of machine-readable symbols.